1. Technical Field
Present invention embodiments relate to data compression, and more specifically, to compressing a set of integers by identifying a common divisor.
2. Discussion of the Related Art
Query performance in a data warehouse is often limited by the time spent reading data from persistent storage devices. To reduce the amount of data that must be read, the data may be stored in compressed forms. In a columnar compression scheme (whether the final arrangement of the compressed data is columnar or not), values from a single column may be grouped together and compressed separately from values of other columns. Existing compression techniques for columns of integer data represent values (or differences between values) in a reduced number of bits if the values are small—effectively trimming off high-order bits that are runs of all-one or all-zero. However, existing techniques do not efficiently trim off runs of low-order bits or exploit other patterns in integer data.